How to Build a Superlens

by David R. Smith Science, 22 Apr 2005 Conventional lenses are subject to the diffraction limit, which means that they cannot resolve objects placed closer together than one-half of the wavelength of the illuminating light. As Smith explains in his Perspective, this limit occurs because conventional optical components leave behind the electromagnetic "near-fields" -- those components that contain the subwavelength spatial information about an object. In 2000, John Pendry proposed a new type of imaging device, based on a material with a negative index of refraction, which could recover the near-fields. Using a thin silver film as a superlens, Fang et al. now demonstrate that negative refraction can indeed produce a high-resolution optical image, opening the door to a new breed of optical devices and applications. Read the article